Apparatus for the hot stretching of threads and especially of synthetic textile filaments



3,266,084 APPARATUS FOR THE HOT STRETCHING OF THREADS AND Aug. 16, 1966x. THERY ESPECIALLY OF SYNTHETIC TEXTILE FILAMENTS Filed Sept 10, 1964 2Sheets-Sheet 1 //v VIVTOR X The!" y ATTORNEYS Aug. 16, 1966 x, THERY3,266,084

APPARATUS FOR THE HOT STRETCHING OF THREADS AND ESPECIALLY OF SYNTHETICTEXTILE FILAMENTS Filed Sept 10, 1964 2 Sheets-Sheet 2 //Vl/E/VTOR X.The r y WM ATTOR NE Y5 United States Patent 3,266,084 APPARATUS FOR THEHUT STRETCHHNG 0F THREADS AND ESPECHALLY 0F SYN- THETIC TEXTILEFILAMENTS Xavier Thery, 132 Rue dYpres, Wambrechies, France Filed Sept.10, 1964, fier. No. 395,435 Claims priority, application France, Sept.11, 1963, 947,224 3 Ciairns. (Cl. 18-1) It is well known that, incontradistinction to natural textile fibers, synthetic fibers having apolyester or polyamide base exhibit, when stretched, not only asubstantial elasticity which prevents maximum utilization of their greatresistance to rupture and wear, but also a permanent elongation whichresults in unacceptable deformations.

It has already been suggested that this elasticity be reduced bysubjecting the synthetic filaments to a controlled stretching processcarried out at a precise temperature.

This treatment which is especially necessary in the case of sewingthread, threads for filters, sieves, or silk-screening processes,synthetic cloths made from continuous filaments, etc., has the effect oforienting its molecules and reducing its elasticity, while retaining itsdynamometric strength.

The present invention relates to an apparatus which permits the abovementioned treatment to be carried out in an advantageous manner.

This invention consists of a new machine which comprises a stretchingdevice which is used especially for synthetic filaments and fibers. Thisdevice is characterized essentially by its use of the combination of acylinder heated to a constant temperature and provided with peripheralgrooves in each of which a filament lies, and two feedingdevices placedupstream and downstream of said drum, the proportion between thetangential speeds of the feeding devices being a function of theelongation sought, and the tangential speed of the drum being preferablyin between the tangential speeds of the feeding devices.

The present invention also has as its object a feeding device which maybe used advantageously with the stretching device defined above, thisfeeding device being characterized essentially by the fact that itcomprises a row of rings having biconical surfaces, so that fibersplaced between two consecutive rings are wedged between these rings.

In the method of construction preferred for the feeding device accordingto the invention, the rings have at one point on their peripheries aslit which permits the easy cutting of any filament which has becomewound up on the feeding device as a consequence, for example, of anaccident.

In order to clearly explain the invention there will now be described by'way of illustration and without limiting the scope of the invention tothe details thereof, one embodiment, taken as an example and illustratedon the accompanying drawings, in which:

FIG. 1 shows schematically a stretching device conforming to theinvention;

FIG. 2 is a longitudinal sectional view of a feeding device conformingto the invention;

FIG. 3 is a section taken along the line IIIIII of FIG. 2; and

FIG. 4 is a partial axial section through the drum.

As may be seen on the drawing, the stretching device according to theinvention consists essentially of the drum 1 and feeding devices 2 and 3respectively, placed upstream and downstream of the drum, and a take-upcylinder assuring that the filaments will follow around the greater partof the periphery of the drum.

The filaments 5 are formed into a layer parallel to one another by comb6 and are directed to feeding device 2 over take-up cylinder 7.

Feeding device 2 leads the filaments at a constant speed over take-upcylinder 4. The filaments then pass over drum 1, after which feedingdevice 3 brings them up to its own speed.

Finally, after having passed over take-up cylinder 8 and over the guides9, the fibers pass over an oiling roller 10, to be then wound on thereels in the usual manner.

As may be seen in FIG. 4 where it is shown cut in half, drum 1 ismounted on the free end of shaft 11 by means of a spider 12 providedformed with a plurality of apertures.

The wall of the drum is constructed of a metal which is a good heatconductor, for example, copper, and its periphery is provided withannular grooves having a substantially triangular section. For examplethe bottoms of these grooves may be 6.5 mm. apart when the grooves are 4mm. deep.

Such a device permits filaments 5 to be isolated perfectly from oneanother while they are wound about the drum.

The drum is heated by four gas burners 13, 14, 15 and 16 which aremounted parallel to each other inside the drum.

From the time that the device is turned on until the desired temperatureis reached, valve 17 is left open so that the four burners 13, 14, 15and 16 function simultaneously. When the operating temperature isreached and a great heating power is therefore no longer necessary,valve 17 is closed by hand so as to cut off burners 13 and 14, onlyburners 15 and 16 being then supplied from the gas inlet pipe 13 throughelectrically operated valve 19.

An auxiliary pipe 20 is provided with a valve 21 through which theburners are supplied at a low rate when the electrically operated valveis closed, so that the temperature may be regulated as will be explainedbelow.

To control the electrically operated valve 19, an expansion gauge 22 isplaced in the wall of drum 1, the electric conductors of which deviceare connected to the electrically operated valve 19 by brushes 23positioned on the rear face of the drum.

Thanks to this device, when the drum reaches a predeterminedtemperature, the expansion gauge acts on valve 19, which closes, thusdrastically decreasing the heating power of burners 15 and 16 which arethen supplied only at a low rate through the auxiliary pipe 20.

inversely, when the temperature of drum 1 drops below the settemperature, electrically operated valve 19 opens and burners 15 and 16again function normally.

The gases produced by the combustion in burners 13, 14, 15 and 16 escapeon each side of the hollow drum. This escape is made possible byopenings in the spider 12 which connects the drum to shaft 11.

Gas heating is not essential and other sources of heat, such aselectricity, are compatible with the invention.

Taking account of the fact that the drum rotates and that it is made of.a metal which is a good heat conductor, it is possible to obtain a highdegree of precision in the regulation of the temperature which istransferred to the filaments, which, as is well known, is essential tothe successful thermal treatment of the filaments.

The device may be improved upon by adding an intermediate cylinder,driven independently of the drum, between the flame and the drumcarrying the threads, so as to avoid partial overheating of the drum,and consequent deterioration of the threads, in case the machine isstopped for a substantial length of time, to repair broken threads, forexample.

As may be seen on FIGS. 2 and 3, the feeding means according to theinvention consists of a shaft 24 supporting a row of biconical rollers25 fixed to the shaft 24 by a key 26.

These rollers are held on the shaft by the nut 27, which permits thefeeding device to be easily disassembled whenever cleaning is necessary.The scraps of thread which accumulate between the rollers may thus beeasily eliminated.

As seen best on FIG. 2, the rollers 25 are biconical in section, so thatthe end portions 25a taper more sharply toward the center than theportions 25b.

Consequently, when a thread is wound on the feeding device between tworollers, it automatically positions itself between adjacent portions25b, as shown at the top of FIG. 2.

It follows that the thread is positively gripped by the feeder, so thatthe speed of the feeder is imparted to the thread.

In accordance with the invention the rollers 25 are provided with a slot28 at one point along their peripheries. These slots register with eachother to form a groove running the full length of the feeder.

These slots 28 make it possible to readily cut any thread which hasbecome accidentally wound around the feeder by introducing a cuttingtool into the slots.

Such an accident may happen Whenever a thread breaks unexpectedly, sinceeach thread is gripped between two feeder rollers.

The fact that threads thus wound up on the roller may be easily cutmakes it possible to get the machine back in operation promptly.

The applicant has made and extensively tested a machine which givescomplete satisfaction and has the following characteristics:

It permits 60 threads to be treated simultaneously, the heating cylinderhas a diameter of 55.5 cm. and it is provided with 60 triangular groovesspaced 6.5 mm. from center to center and 4 mm. deep. As has previouslybeen explained, the cylinder projects from a spider provided with 8openings, and its inner diameter is about 35 cm. It is driven at a speedwhich may be controlled by a dc vice known as a horses head.

The stretching devices consist of a stack of 61 disks so shaped that,when they are brought up against each other, the angle between theadjacent faces which are to grip the thread is 9".

The stretching devices are driven from the shaft which drives the drumthrough two variable speed transmissions so that if the drum isconsidered to turn at a speed of 100 units, the speed of the feedingdevice upstream of the drum may be varied between 84 and 100 units andthat of the feeder downstream of the drum at between 100 and 128 units.

During the heating period the drum is driven at a reduced speed by anauxiliary motor at the rate of about one revolution every five minutes,so that the drum will be uniformly heated.

With means such as that which has been described for regulating thetemperature of the drum, this temperature 4 is maintained within a rangeof about plus or minus 1.5 C.

For example, continuous filament nylon of 210/2 deniers (21,500meters/kg.) has been treated on this machine at a speed of 41meters/minute, so that the machine handles about 6.9 kg. of material perhour.

Continuous filament tergal of 250/3 deniers (10,600 meters/ kg.) hasalso been treated at a speed of 26 meters/ minute, so that the machinehandled 8.8 kg. of material per hour.

Discontinuous tergal fibers of 88/3 deniers (31,000 meters/kg.) havealso been treated at a speed of 72 meters/ minute, so that the machinehandled about 8.3 kg. of material per hour.

It will of course be appreciated that the embodiments which have beendescribed were given purely by way of example and may be modified as todetail without thereby departing from the basic principles of theinvention.

In particular, it is obvious that the specific heating means does notconstitute an essential feature of the invention and other heating meansmay be substituted therefor.

Similarly, the feeding devices which have been described, whileespecially suited for use with the stretching device of the invention,may also be replaced by other types of feeding means.

What is claimed is:

1. A device for stretching textile threads, said device comprising aheated rotatably mounted drum provided with a plurality of peripheralgrooves for receiving said threads, rotatably mounted guiding means forsaid threads positioned upstream and downstream of said heated drum, andmeans for rotating said drum and guiding means at different speeds withthe downstream guiding means turning at a tangential speed greater thanand the upstream guiding means at a tangential speed less than that ofsaid drum, each guiding means comprising a row of parallel discs whichtouch each other at their central portions, the principal surfaces ofsaid discs sloping away from said central portions so that threads ledbetween said discs are gripped thereby.

2. A device as claimed in claim 1 in which the discs of each guidingmeans are removably mounted on a central pin.

3. A device as claimed in claim 1 in which said discs are provided withregistering transverse notches which define a recess parallel to saidpin for receiving a knife.

References Cited by the Examiner UNITED STATES PATENTS 1,962,028 6/1934Murphy et al. 2,307,056 1/ 1943 Minich 264-288 2,745,134 5/1956 Collins18-1 3,095,606 2/1963 Scott 181 X FOREIGN PATENTS 833,756 4/1960 GreatBritain.

37/12,7l1 9/1962 Japan.

WILLIAM J. STEPHENSON, Primary Examiner.

1. A DEVICE FOR STRETCHING TEXTILE THREADS, SAID DEVICE COMPRISING AHEATED ROTATABLY MOUNTED DRUM PROVIDED WITH A PLURALITY OF PERIPHERALGROOVES FOR RECEIVING SAID THREADS, ROTATABLY MOUNTED GUIDING MEANS FORSAID THREADS POSITIONED UPSTREAM AND DOWNSTREAM OF SAID HEATED DRUM, ANDMEANS FOR ROTATING SAID DRUM AND GUIDING MEANS AT DIFFERENT SPEEDS WITHTHE DOWNSTREAM GUIDING MEANS TURNING AT A TANGENTIAL SPEED GREATER THANAND THE UPSTREAM GUIDING MEANS AT A TANGENTIAL SPEED LESS THAN THAT OFSAID DRUM, EACH GUIDING MEANS COMPRISING A ROW OF PARALLEL DISCS WHICHTOUCH EACH OTHER AT THEIR CENTRAL PORTIONS, THE PRINCIPAL SURFACES OFSAID DISCS SLOPING AWAY FROM SAID CENTRAL PORTIONS SO THAT THREADS LEDBETWEEN SAID DISCS ARE GRIPPED THEREBY.